Myopia is the most common childhood refractive disorder. Atropine inhibits myopia progression, but its mechanism is unknown. Here, we show that myopia-prevention by atropine requires production of nitric oxide (NO). Form-deprivation myopia (FDM) was induced in week-old chicks by diffusers over the right eye (OD); the left eye (OS) remained ungoggled. On post-goggling days 1, 3, and 5, OD received intravitreally 20 µL of phosphate-buffered saline (vehicle), or vehicle plus: NO source: L-arginine (L-Arg, 60-6,000 nmol) or sodium nitroprusside (SNP, 10-1,000 nmol); atropine (240 nmol); NO inhibitors: L-NIO or L-NMMA (6 nmol); negative controls: D-Arg (10 µmol) or D-NMMA (6 nmol); or atropine plus L-NIO, L-NMMA, or D-NMMA; OS received vehicle...

In the presence of optical blur at the fovea, blur adaptation can improve visual acuity (VA) and perceived image quality over time. However, little is known regarding blur adaptation in the peripheral retina. Here, we examined neural adaptation to myopic defocus at the fovea and parafovea (10° temporal retina) in both emmetropes and myopes. During the 60-min adaptation period, subjects (3 emmetropes and 3 myopes) watched movies with +2 diopters of defocus blur through a 6-mm artificial pupil in two separate, counter balanced sessions for each retinal location...

OBJECTIVE: To assess the visual outcomes after cataract surgery among urban and rural population aged ≥40 years in the South India state of Andhra Pradesh. METHODS: A population based cross-sectional study was conducted in which 7800 subjects were sampled from two rural and one urban location. Visual Acuity was assessed and eye examination were performed by trained personnel. A questionnaire was used to collect personal and demographic information, and history of cataract surgery...

PURPOSE: To evaluate the long term effect of oral isotretinoin therapy on macula ganglion cell complex (GCC) thickness by spectral domain optical coherence tomography (SD-OCT). MATERIALS AND METHODS: Newly diagnosed cystic acne patients who received low dose for a long time systemic isotretinoin therapy were included to study. Thorough ophthalmic evaluation and GCC thickness analysis by using SD-OCT were performed at baseline, and at 1, 3, 6, and 12 months of treatment...

OBJECTIVE: To investigate the influence of creating a flap on the postoperative optical quality of the cornea in terms of predicted corneal curvature and Seidel aberrations after 2 modalities of femtosecond assisted corneal lenticule extraction laser for the correction of myopia and myopic astigmatism: The flapless procedure small incision lenticular extraction (SMILE) and the flap-based femtosecond lenticular extraction (FLEx). METHODS: The study is a prospective consecutive non-randomised comparative interventional case series including 64 eyes with myopic or myopic astigmatism refractive errors...

Retinopathy of prematurity (ROP) is an emerging cause of childhood blindness in low- and middle-income countries. We review the magnitude, causes, prevention and treatment of visual impairment caused by ROP over a time span. A review of literature on short and long term structural and functional outcomes of ROP was conducted through PubMed search primarily focusing on studies published during the last decade. Additionally, we have shared data from our institute located in Southern India. Visual Impairment in ROP-treated children ranged from 4...

Attenuation of ultrasound waves traversing a medium is not only a result of absorption and scattering within a given tissue, but also of coherent scattering, including diffraction, refraction, and reflection of the acoustic wave at tissue boundaries. This leads to edge enhancement and other artifacts in most reconstruction algorithms, other than 3D wave migration with currently impractical, implementations. The presented approach accounts for energy loss at tissue boundaries by normalizing data based on variable sound speed, and potential density, of the medium using a k-space wave solver...

AIM: To study the concentration of cytokines in the aqueous humor of the anterior chamber in patients with myopic choroidal neovascularization (mCNV) and to compare the results to their ophthalmic status. MATERIAL AND METHODS: A total of 19 patients (19 eyes) with mCNV treated with intravitreal ranibizumab were included in the study. The control group consisted of 15 patients (15 eyes) with myopia who had cataract surgery. Age, sex, and refractive error distribution were similar to that in the study group...

PURPOSE: To detect corneal inflammation and apoptosis induced after small incision lenticule extraction (SMILE) at different refractive corrections for moderate to high values of myopia. METHODS: Fifty patients (50 eyes) suffering from medium to high myopia (spherical equivalent refraction from -3.75 to -10.00 diopters (D) with refractive astigmatism under -0.75 D) underwent SMILE in order to correct myopic error. In vivo evaluation was done by corneal confocal microscopy (IVCM) and ex vivo by immunohistochemistry...

Laser in-situ keratomileusis (LASIK) is safe and effective laser refractive procedures in treating refractive errors. However, regression of treatment and iatrogenic keratectasia remain to be a major concern, especially in treating thin cornea with high ametropia. Collagen cross-linking (CXL) is an effective method in stopping keratoconus progression through increasing the biomechanical strength of the cornea. Adjuvant cross-linking to refractive procedures can theoretically help prevent regression and reduce the risk of keratectasia development by increasing the mechanical stability of cornea...

PURPOSE: To determine the difference between cycloplegic and non-cycloplegic refractive error and its associated factors in Chinese children and adolescents with a high prevalence of myopia. METHODS: A school-based study including 1565 students aged 6 to 21 years was conducted in 2013 in Ejina, Inner Mongolia, China. Comprehensive eye examinations were performed. Pre-and postcycloplegic refractive error were measured using an auto-refractor. For cycloplegic refraction, one drop of topical 1...

AIM: The purpose of this study is to establish a normative database of subfoveal choroidal thickness (CT) in healthy young Indians using spectral domain optical coherence tomography (SD OCT). Evaluation and comparison of CT of central serous chorioretinopathy (CSC) and fellow eyes were also performed. MATERIALS AND METHODS: This was a prospective, cross-sectional, and observational study. It included 112 normal eyes of 112 healthy volunteers who had no evidence of ocular or systemic disease, 84 CSC eyes with acute, treatment-naïve CSC, and 69 fellow eyes with no evidence of neurosensory detachment or pigment epithelium detachment on SD OCT...

AIM: The aim of this study was to compare the results of enhanced Brückner test (EBT) performed by a pediatrician and an experienced pediatric ophthalmologist. SUBJECTS AND METHODS: In this prospective double-masked cohort study, a pediatrician and a pediatric ophthalmologist performed the EBT in a classroom of a school in semi-dark lighting condition using a direct ophthalmoscope. The results of the test were compared using 2 × 2 Bayesian table and kappa statistics...

Myopia is a generally benign refractive error with an increasing prevalence worldwide. It can be corrected temporarily with glasses and contact lenses and permanently with laser vision correction. The 2 main procedures currently being performed for myopia correction are photorefractive keratectomy and laser-assisted in situ keratomileusis. Each technique has its advantages, but they appear to yield similar visual outcomes 1 year after surgery. Laser vision correction for myopia was considered a paradigm shift because healthy eyes could now undergo a surgical procedure to permanently and safely correct the error by altering the center of the cornea, which was previously off limits because of the potential for loss of transparency...

The prevalence of myopia in developed countries in East and Southeast Asia has increased to more than 80% in children completing schooling, whereas that of high myopia has increased to 10%-20%. This poses significant challenges for correction of refractive errors and the management of pathological high myopia. Prevention is therefore an important priority. Myopia is etiologically heterogeneous, with a low level of myopia of clearly genetic origins that appears without exposure to risk factors. The big increases have occurred in school myopia, driven by increasing educational pressures in combination with limited amounts of time spent outdoors...

Myopia is not a simple refractive error, but an eyesight-threatening disease. There is a high prevalence of myopia, 80% to 90%, in young adults in East Asia; myopia has become the leading cause of blindness in this area. As the myopic population increases globally, the severity of its impact is predicted. Approximately one fifth of the myopic population has high myopia (≥-6 diopters), which results in irreversible vision loss such as retinal detachment, choroidal neovascularization, cataracts, glaucoma, and macular atrophy...

BACKGROUND: Tobacco smoking has detrimental influence on human health and is one of the leading causes of preventable mortality worldwide, associated with lung cancer, chronic obstructive lung disease and cardiovascular disease. AIM: The analysis of the influence of tobacco smoking on pathology of the anterior segment of the eye in adults and children. METHODS: A comprehensive review of the literature performed through MEDLINE and PubMed searches, was published during the period 2000-2016...